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Location-based algorithms for finding sets of corresponding objects over several geo-spatial data sets / E. Safra in International journal of geographical information science IJGIS, vol 24 n°1-2 (january 2010)
[article]
Titre : Location-based algorithms for finding sets of corresponding objects over several geo-spatial data sets Type de document : Article/Communication Auteurs : E. Safra, Auteur ; Yaron Kanza, Auteur ; Y. Sagiv, Auteur ; et al., Auteur Année de publication : 2010 Article en page(s) : pp 69 - 106 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] analyse comparative
[Termes IGN] classification barycentrique
[Termes IGN] imprécision géométrique
[Termes IGN] intégration de données
[Termes IGN] jeu de données localisées
[Termes IGN] jointure spatiale
[Termes IGN] objet géographiqueRésumé : (Auteur) When integrating geo-spatial data sets, a join algorithm is used for finding sets of corresponding objects (i.e., objects that represent the same real-world entity). This article investigates location-based join algorithms for integration of several data sets. First, algorithms for integration of two data sets are presented and their performances, in terms of recall and precision, are compared. Then, two approaches for integration of more than two data sets are described. In one approach, all the integrated data sets are processed simultaneously. In the second approach, a join algorithm for two data sets is applied sequentially, either in a serial manner, where in each join at least one of the joined data sets is a single source, or in a hierarchical manner, where two join results can be joined. For the two approaches, join algorithms are given. The algorithms are designed to perform well even when location of objects are imprecise and each data set represents only some of the real-world entities. Results of extensive experiments with the different approaches are provided and analyzed. The experiments show the differences, in accuracy and efficiency, between the approaches, under different circumstances. The results also show that all our algorithms have much better accuracy than applying the commonly used one-sided nearest-neighbor join. Copyright Taylor & Francis Numéro de notice : A2010-113 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1080/13658810802275560 En ligne : http://dx.doi.org/10.1080/13658810802275560 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30309
in International journal of geographical information science IJGIS > vol 24 n°1-2 (january 2010) . - pp 69 - 106[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-2010012 RAB Revue Centre de documentation En réserve L003 Disponible 079-2010011 RAB Revue Centre de documentation En réserve L003 Disponible Modelling vertical error in LiDAR-derived digital elevation models / F. Aguilar in ISPRS Journal of photogrammetry and remote sensing, vol 65 n° 1 (January - February 2010)
[article]
Titre : Modelling vertical error in LiDAR-derived digital elevation models Type de document : Article/Communication Auteurs : F. Aguilar, Auteur ; Jon Mills, Auteur ; J. Delgado, Auteur ; et al., Auteur Année de publication : 2010 Article en page(s) : pp 103 - 110 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] interpolation inversement proportionnelle à la distance
[Termes IGN] lasergrammétrie
[Termes IGN] modèle d'erreur
[Termes IGN] modèle numérique de surfaceRésumé : (Auteur) A hybrid theoretical–empirical model has been developed for modelling the error in LiDAR-derived digital elevation models (DEMs) of non-open terrain. The theoretical component seeks to model the propagation of the sample data error (SDE), i.e. the error from light detection and ranging (LiDAR) data capture of ground sampled points in open terrain, towards interpolated points. The interpolation methods used for infilling gaps may produce a non-negligible error that is referred to as gridding error. In this case, interpolation is performed using an inverse distance weighting (IDW) method with the local support of the five closest neighbours, although it would be possible to utilize other interpolation methods. The empirical component refers to what is known as “information loss”. This is the error purely due to modelling the continuous terrain surface from only a discrete number of points plus the error arising from the interpolation process. The SDE must be previously calculated from a suitable number of check points located in open terrain and assumes that the LiDAR point density was sufficiently high to neglect the gridding error. For model calibration, data for 29 study sites, 200*200 m in size, belonging to different areas around Almeria province, south-east Spain, were acquired by means of stereo photogrammetric methods. The developed methodology was validated against two different LiDAR datasets. The first dataset used was an Ordnance Survey (OS) LiDAR survey carried out over a region of Bristol in the UK. The second dataset was an area located at Gador mountain range, south of Almería province, Spain. Both terrain slope and sampling density were incorporated in the empirical component through the calibration phase, resulting in a very good agreement between predicted and observed data (R2=0.9856;p Numéro de notice : A2010-233 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2009.09.003 En ligne : https://doi.org/10.1016/j.isprsjprs.2009.09.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30427
in ISPRS Journal of photogrammetry and remote sensing > vol 65 n° 1 (January - February 2010) . - pp 103 - 110[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2010011 SL Revue Centre de documentation Revues en salle Disponible Monitoring of the bouillante geothermal exploitation (Guadeloupe, French West Indies) and the impact on its immediate environnement / Bernard Sanjuan (2010)
Titre : Monitoring of the bouillante geothermal exploitation (Guadeloupe, French West Indies) and the impact on its immediate environnement Type de document : Article/Communication Auteurs : Bernard Sanjuan, Auteur ; Philippe Jousset, Auteur ; Gwendoline Pajot-Métivier , Auteur ; et al., Auteur Editeur : International geothermal association Année de publication : 2010 Conférence : World Geothermal Congress 2010 25/04/2010 29/04/2010 Bali Indonésie OA Proceedings Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géophysique interne
[Termes IGN] énergie géothermique
[Termes IGN] géothermie
[Termes IGN] Guadeloupe
[Termes IGN] surveillance géologiqueRésumé : (auteur) The Bouillante high enthalpy geothermal field, 250-260°C, is located in the Guadeloupe volcanic Island (French West Indies). Since 2005, the new geothermal power plant has had an installed capacity of 15 MWe gross which represents about 8% of the annual electricity needs in the Island. It is supplied by 3 wells which can produce up to 120 tons/h of steam. No residual water is re-injected. Among the research efforts carried out by the BRGM group and partially funded by ADEME (French Environment and Energy Management Agency), different monitoring methods of the geothermal exploitation have been started, tested and developed in order to optimize and secure electricity production and to control its impact on the immediate environment of the power plant. This is especially important because the power plant is located inside the Bouillante town. These methods are: geochemical monitoring of the fluids collected from the geothermal wells and neighboring thermal springs in order to control the evolution of the fluid geochemistry and the Gas/Steam Ratio, surface soil thermometry monitoring, geophysical monitoring such as broadband seismology, microgravity and SAR interferometry to detect mass transfers or changes in the geothermal reservoir during its exploitation as well as vertical surface ground deformations. This paper presents the main results and conclusions obtained from these different monitoring techniques. On the whole, despite the pressure decrease observed in the geothermal reservoir due to an annual production estimated at about 4.5 millions of tons of fluid, no significant variation of the monitored parameters has been detected from these methods during four quasi-continuous years of geothermal exploitation. Most of these monitoring techniques will be continued and probably developed in the next few years, especially if the produced fluids are re-injected, in order to anticipate and/or quickly take into account problems such as issues related to chemical change of the reservoir fluid or induced microseismicity. Numéro de notice : C2010-070 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Communication DOI : sans En ligne : http://www.geothermal-energy.org/pdf/IGAstandard/WGC/2010/2407.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102052 Documents numériques
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Titre : PPP, Precise Point Positioning : constraints and opportunities Type de document : Article/Communication Auteurs : Katrin Huber, Auteur ; F. Heuberger, Auteur ; Christoph Abart, Auteur ; et al., Auteur Editeur : Fédération Internationale des Géomètres FIG - International Federation of Surveyors FIG Année de publication : 2010 Conférence : FIG 2010, international congress Facing the Challenges – Building the Capacity 11/04/2010 16/04/2010 Sydney Australie OA proceedings Importance : 17 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] convergence
[Termes IGN] géonavigateur
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur GNSSRésumé : (Auteur) Precise Point Positioning (PPP) is a satellite based positioning technique aiming at highest accuracy in close to real-time. First investigations using dual frequency data from a single GPS receiver data for a few cm-positioning in post-processing mode have been published in 1997 by JPL. Utilizing the ionosphere free linear combination the remaining required model information like precise orbits and clocks issued by the IGS has been used. Within the last decade a number of approaches have been carried out to serve applications in close to realtime by this technique. In comparison with common techniques like DGPS or RTK, the costs are reduced, because no base stations and no simultaneous observations are necessary. On the other hand the necessary models have to be fetched either from globally acting services like IGS (orbits, satellite clocks) or from regional GNSS service providers (atmospheric delays) and standard interfaces (e.g. RTCM) have to be developed to forward this information to the rover. Further problems still to be solved are coordinate convergence periods of up to 2 hours as well as ambiguity resolution, which are harmed by non-integer calibration phase biases. These biases vanish only in difference mode and have to be determined a priori. The main focus of the research presented in this paper is to enhance the actual achievable accuracy of PPP and to reduce convergence time. Therefore detailed investigations on new PPP algorithms and methods are carried out within the project RA-PPP (Rapid Precise Point Positioning) focusing on the derivation of improved ionospheric models providing a better accuracy for single frequency users and on the use of “regional clocks” - a method to further enhance the positioning accuracy. Furthermore, linear combinations making use of new GNSS signals are investigated to improve the noise behavior with respect to commonly used linear combinations. Additionally, a PPP software module that applies the developed algorithms and techniques to real GNSS data is developed during the research project. PPP is performed by means of a commercial GNSS receiver supported by a small processing device, but much improved accuracies than operating in standard positioning mode can be achieved. Several testing and verification routines evaluate the performance of applied algorithms and individual calculation steps. Also a later modification with regard to GNSS modernization (new signals) is considered. Finally several fields of application, where the PPP technique is nowadays used and can be used in the future are presented. Numéro de notice : 14267 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Communication Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=64329 Documents numériques
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14267_ppp_huber-et-al_4040.pdfAdobe Acrobat PDF Preliminary works on creation of the new geoid model HRG2009 / I. Grgic (01/01/2010)
contenu dans Second proceedings of the Croatian Geodetic Institute for the period 2006-2009 / Croatian geodetic institute (2010)
Titre : Preliminary works on creation of the new geoid model HRG2009 Type de document : Article/Communication Auteurs : I. Grgic, Auteur ; M. Lucic, Auteur ; Marija Repanic, Auteur ; et al., Auteur Editeur : Zagreb [Croatie] : Croatian geodetic institute Année de publication : 01/01/2010 Conférence : CGI 2009, 2nd proceedings of the Croatian Geodetic Institute for the period 2006-2009 11/04/2010 16/04/2010 Zagreb Croatie OA proceedings Importance : pp 303 - 312 Note générale : Bibliographie Langues : Anglais (eng) Serbo-croate (Latin) (scr) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Croatie
[Termes IGN] géoïde altimétrique
[Termes IGN] géoïde local
[Termes IGN] nivellement
[Termes IGN] positionnement par GNSSRésumé : (Auteur) The official Croatian geoid model HRG2000 was developed as a surface for con--version of GNSS-derived ellipsoidal heights into orthometric heights. CROatian POsitionig System (CROPOS), based on 30 permanently working GNSS reference station, had been esta-blished last year. Since HRG2000 geoid model characterizes some weaknesses regarding abso-lute orientation we have used CROPOS service to define new points which will be a base for creation of the new Croatian geiod model HRG2009. For this purpose over the whole Croatian territory more than 500 GNSS/levelling geodetic points were stabilized and measured according to the approximate raster of10x10km. All measured points were connected to the nearest ben-chmarks of the new Croatian vertical datum by precise levelling. The GNSS/Levelling survey provides reliable geoid undulation but only at the points where the survey is made. Therefore for the construction of an accurate HRG2009 geoid model afterwards the gravimetric geo-id model, which should be calculated from all new measured gravity points and old availa-ble gravity data, will befitted to the geoid undulation data from a GNSS/levelling survey. The recently determined geoid undulation calculated from GNSS/Levelling data at the measured geodetic points were analyzed additionally in relation to the geoid undulation from the geoid model HRG2000. The range of geoid undulation and orthometric height differences at measu-red points between old and new geoid model shows an important progress concerning quality in definition of heights for the Republic of Croatia. Numéro de notice : C2009-014 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Communication Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=65054 Quand des Bidachots racontent ... Bidache / Jean-Jacques Lasserre (2010)PermalinkPermalinkA semantic registry using a feature type catalogue instead of ontologies to support spatial data infrastructures / K. Stock in International journal of geographical information science IJGIS, vol 24 n°1-2 (january 2010)PermalinkSpace-time reference systems for monitoring global change and for precise navigation / Axel Nothnagel (2010)PermalinkPermalinkUnderstanding sea-level rise and variability / J.A. Church (2010)PermalinkUnderstanding sea-level rise and variability, ch 9. Geodetic observations and global reference frame contributions to understanding sea-level rise and variability / Geoffrey Blewitt (2010)PermalinkUsing building permits to monitor disaster recovery: a spatio-temporal case study of coastal Mississipi following hurricane Katrina / J. Stevenson in Cartography and Geographic Information Science, vol 37 n° 1 (January 2010)PermalinkAmundsen Sea bathymetry: the benefits of using gravity data for bathymetric prediction / M. Mcmillan in IEEE Transactions on geoscience and remote sensing, vol 47 n° 12 Tome 2 (December 2009)PermalinkAugmenting the Iterative Closest Point (ICP) alignment algorithm with intensity / S. Hefford in Geomatica, vol 63 n° 4 (December 2009)Permalink